Void* arithmetics example

BubbleSort.cpp

#include<iostream>
#include<cstring> 
 
using namespace std;
 
int sortAscending(const void* A, const void* B);
int sourtDouble(const void* A, const void* B);
void bubbleSort(void * base, size_t num, size_t size, int (*compare)(const void*, const void*));
 
int main(int argc, char* argv[])
{
  int values [] = { 88, 56, 100, 2, 25 };
   
  for(int i=0; i < 5; ++i)
    cout << *(values + i) << " ";
   
  cout << endl;
   
  bubbleSort(values, 5, sizeof(int), sortAscending);
   
  for(int i=0; i < 5; ++i)
    cout << *(values + i) << " ";
   
  cin.get();
  
  double val[] = { 88.5 , 56.2, 100.02, 2.1, 25.9};
  
  for(int i=0; i<5; ++i)
  	cout << *(val+i) << " ";
  
  cout << endl;
  
  bubbleSort(val, 5, sizeof(double), sourtDouble);
  
  for(int i=0; i<5; ++i)
    cout << *(val+i) << " ";
  
  return 0;
}
 
int sortAscending(const void * A, const void * B)
{
  if( *((int*)A) > *((int*)B)) return 1;
  if( *((int*)A) < *((int*)B)) return -1;
 
return 0;
}

int sourtDouble(const void *A, const void *B)
{
  cout << "Comparer has: " << *((double*)A) << " " <<*((double*)B) << endl ;
 
  if( *((double*)A) > *((double*)B)) return 1;
  if( *((double*)A) < *((double*)B)) return -1;
 
  return 0;
}
 
void bubbleSort(void * base, size_t num, size_t size, int (*compare)(const void*, const void*))
{
  void* A;
  void* B;
  void* tmp = malloc(size);
   
  
  int n = num;
  do{
    for(int i=0; i < n-1; ++i)
    {
      A = static_cast<char*>(base) + i*size;
      B = static_cast<char*>(base) + (i+1)*size;
      if( compare( A, B) == 1)
      {
        //Swap
        memset(tmp,0,size);
        memcpy (tmp, A, size);
        memcpy (A, B, size);
        memcpy (B, tmp, size);
      }
    }
    --n;
  }while(n > 1);
  
  free(tmp);
}